The desire to alter the world to suit our needs is a seemingly defining characteristic of human beings. And as these images from the Royal Geographical Society archives show, we’re not afraid to think big: whether it’s damming the Euphrates or cutting across an entire continent to link two oceans. While these constructions were often seen as triumphs of human engineering and ingenuity, they were also often human tragedies, with tens of thousands of workers losing their lives toiling under appalling conditions